Do you know anything about TMPGEnc 2.5's special "Canopus DV Codec setting" section in the Environmental Settings? Now that I have a Canopus ADVC110 for capture, I am thinking maybe I should pay attention to those but am clueless what any of them mean.

The "enable reading referrd (sic) format" option shouldn't be relevant these days (it says "always on", which suggests you can't even toggle it).

The "interpolate YUV data" option also shouldn't make a difference; I expect TMPGEnc will do that internally, with a quality at least as good as Canopus' codec (BTW, it's odd it says specifically 4:1:1, since PAL DV uses 4:2:0). It might make a slight difference in terms of encoding time, though; you'll have to try it.

The final option is the only one you need to be careful with. As described in the compression guide, TMPGEnc has an option (in the "Advanced") tab to select between "Basic YCbCr" (meaning use the values as they come) and "video-corrected" values (which limits the brightness and saturation of the pixels to video-safe levels).

So that setting and this setting must be "compatible" or your image will end up too bright and saturated (or too dark and unsaturated).

Following normal terminology and standards, you should use one of these combinations:

However, this is assuming the Canopus codec behaves in a logical way (which isn't at all guaranteed). It might very well do exactly the opposite of what the options say (i.e., convert from that colour space, instead of to).

So my suggestion would be to do a test, using the following combinations:

Use a clip with very bright and saturated colours, to make the differences more obvious, then record the encoded versions to a DVD (use a DVD-RW, so you don't waste a disc) and play them back on a set-top player connected to a TV set (not a computer monitor, which is not based on the CCIR specification).